1. Field of the Invention
This invention generally relates to fasteners, and more particularly, to an improved hole-filling three-prong temporary fastener for more precisely and securely temporarily holding two or more parts, such as sheet materials, together.
2. Description of the Prior Art
It is well known to use fasteners to temporarily hold and clamp parts together while other operations are performed on the parts. For example, temporary fasteners are used in the aerospace industry to temporarily attach sheets forming the skin of an aircraft to each other, a flange and/or an airframe. Furthermore, such temporary fasteners may be used to hold sheet metal parts together in many other industries. Since it is expensive and time consuming to temporarily fasten parts together using conventional mechanical devices, such as nuts and bolts, rivets and the like, a number of temporary fasteners, including spring loaded devices operated by mechanical tools have been developed.
Known temporary fasteners, particularly those used in the aerospace industry, are only accessible from one side of the parts to be fastened together. Such temporary fasteners may include those referred to as Cleco fasteners, which are plier-operated spring-loaded fasteners for smaller holes or openings having 2 laterally spreadable clamping pins mounted in a cylindrical body for reciprocal movement through an opening in an end past a stationary pin mounted between the clamping pins. The pliers engage a flange on the fastener body and the rearward projecting end of the fastener to compress an internal spring to advance the clamping pins into openings, the pressure is then released and the clamping pins will retract while expanding over the stationary pin so that clamping pins temporarily hold parts together.
Other types of temporary fasteners for larger openings may include so-called wedge locks or Quad-Locks that include threaded actuators and contain 4 laterally spreadable clamping pins. Examples of temporary fasteners for larger openings are also shown in U.S. Pat. No. 3,426,399 to Jones and U.S. Pat. No. 4,934,885 to Woods et al. The Cleco fasteners and the fasteners set forth in these patents are useful in many situations, but do not act to properly fill and/or align pilot holes (also referred to as “coordinated holes”, “digital preassembly holes” or “mating holes”) drilled or otherwise formed in mating parts that require accurate and precise alignment during assembly.
Furthermore, known temporary fasteners tend to vibrate out of position during drilling and/or other mechanical processes performed on parts temporarily held together. Therefore, there exists a need in the art for temporary fastening devices that are easy to use and which more accurately and securely holds parts together during fastening processes, including automated processes.